1. Field of the Invention
The present invention relates to a laminated ceramic electronic component with internal electrodes. Specifically, the present invention relates to a multilayer ceramic capacitor (MLCC) that has been reduced in size and increased in capacity by providing the internal electrodes as thin layers and stacking them densely.
2. Description of the Related Art
As mobile phones and other digital electronic devices become increasingly smaller and thinner, laminated ceramic electronic components that are surface-mounted on electronic circuit boards, etc., are getting smaller. In particular, multilayer ceramic capacitors that are laminated ceramic electronic components are seeing growing needs every year for capacity increase to support decreasing chip sizes. Multilayer ceramic capacitors have a structure whereby dielectric ceramic layers and internal electrode layers are stacked alternately.
In general, reducing the capacitor size inevitably reduces the area of the electrode layers facing the dielectric layers and therefore decreases the capacitance. Accordingly, it is essential, in ensuring enough capacitance of the capacitor to support decreasing chip sizes, to make the dielectric layers and electrode layers thinner and incorporate technology to densely stack them in multiple layers. In particular, the capacity of the capacitor is not affected by the thickness of the electrode layers and therefore it is desirable to make the electrode layers as thin as possible in order to reduce the chip size.
With a ceramic capacitor of densely stacked layers, however, there is a problem in that the thinner the internal electrode layers, the smaller the coverage becomes and the incidence of structural defects rises as a result. Additionally, a decrease of reliability, such as an increase of the probability of shorting of the multilayer ceramic capacitor, also tends to occur.
Prior art is already known that attempts to improve the coverage of a multilayer ceramic capacitor (refer to Patent Literature 1, for example). According to Patent Literature 1, occurrence of structural defects can be suppressed with a multilayer ceramic capacitor whose dielectric layers are 3 μm or thinner and whose internal electrode layers are 0.5 μm to 1.5 μm thick, by adjusting the average size of nickel crystal, which is the primary component of the internal electrode layer, to a range of 0.1 μm or more and 1.5 μm or less.
In addition, Patent Literature 2 discloses another prior art claiming that, by adjusting the average line roughness at the center of the interface between the dielectric layer and internal electrode layer to a range of 20 nm or more and 100 nm or less, a multilayer ceramic capacitor exhibiting excellent longevity under high-temperature load can be achieved.